Syndicate

Repair

First generation Prius (model years 2001, 2002, 2003) typically need a new battery by 150,000 miles, depending on how often they are driven. When the cars are driven regularly (every day, for instance) the batteries tend to last longer; we have several customers with the original battery well over 220k miles. Cars driven rarely can need batteries sooner. But it’s impossible to predict. For more information on battery failure, click here.

However, since battery replacement is common, when HV problems arise it is equally common that the battery is condemned prematurely. This is the case of two DTCs (diagnostic trouble codes) P3009 and P3030. If your car has either of these codes, we can repair the car for MUCH LESS MONEY while confirming that the battery itself is still usable. The following blog is dedicated to P3030.

For more information on P3009 related to the battery, click here.
For more information on P3009 related to the transmission, click here.

P3030 translates to “High Voltage Line Snapped”. It sets whenever the HV Battery ECU detects an open circuit to one of the battery blocks. The Prius battery has bus bars that run down either side of the pack, to connect the modules in series; on one side of the battery it also runs “sensing wires” to each bus bar (effectively monitoring every two modules, which it calls a “block”). This is how the computer keeps track of total battery voltage (by summing the values of all the blocks) and the balance of those blocks.

(Pic of “freeze frame”, a data snapshot, when P3030 set. Note the loss of voltage reading at block 10 (0.83v), but also that the car substitutes a max voltage value (20v) at the previous block, 9. I am not sure why this is the case, but it happens at whatever block is just before the one with the broken wire. I assume it has something to do with how the ECU calculates voltage from one block to the next, but it also makes sense that it would max another value to help compute total battery voltage.)

At this point you know there is a broken or corroded circuit in the harness, creating an open. The sensing circuits are very small 22 gauge wires connected to thin flat tabs that mount at the bus bars, which are easily fractured.

The fracture can be fine enough to create intermittent continuity or simply increase resistance in the circuit, such that the Battery ECU confuses the reduced voltage for a weakened cell. In this case the vehicle will also set DTC P3006. This is VERY VERY important because most techs will interpret P3006 as a bad battery at face, when really the problem is the sensing wire.

Being able to differentiate between a valid P3006 and a bogus one is, frankly, a matter of experience: how many battery failures has a technician seen? Does this look like a typical weak battery or are the values strong, with only occasional voltage drop outs? The “signature” of a failing battery is wide voltage swings under load (heavy assist or heavy regen) either between blocks or across the battery as a whole.

Whether the issue is a harness or the whole battery (or corrosion versus a whole battery, such as DTC P3009), the dealer approach is just replace the whole thing. After all, a new battery will include a new harness, and have no corrosion. No one will know the difference. And wasn’t the car going to need it soon anyway?

Here at LG, we see a worthy and reliable repair.

A new battery—from the dealer or LG—is $3000 out the door. A rebuilt battery, from LG, is $2365. Compare that to:

Owners of 2006-2009 Toyota Prius equipped with HID (high intensity discharge) headlights will receive an apology letter from Toyota this month, in response to their overpriced parts and/or incompetence. Toyota has reduced the price of the bulbs to $150 from $300, and will reimburse anyone the difference who paid more than $150 for one. They will also reimburse you for any charges incurred to replace the headlight control computer (ECU) in case a dealer technician misdiagnosed the problem.

If you had your bulbs replaced here, at Luscious Garage, you are not eligible for this reimbursement because we have always charged around $100 per bulb, which is less than Toyota charges even after this good will campaign. Yes, ours are OE Philips D4R XenEco brand, the exact same as Toyota sells. Current price is $94. And no, we have never sold a Headlight ECU. Why would we? It’s common knowledge that the problem is just the bulbs.

But what of the installation price, which is repeatedly quoted at $250-$300, allegedly to “pull the front clip” (front bumper) to access the bulbs? The Toyota letter mentions nothing of that crooked sales pitch. As I have said to many customers here in person, if the dealer technicians are actually pulling the bumper to replace the bulbs, they are idiots. I am quite sure they are not, rather replacing the bulbs from above (which is what we do, which takes 10 minutes or so), which only makes them crooks. But I would rather have a crook working on my car than an idiot.

Needless to say, here at LG, you don’t have to deal with crooks or idiots. We continue to charge $30 for installation per bulb. Price of bulb, install, and tax, out the door, is $132.93.

All hybrids have two electrical systems, low and high voltage. Low is 12v and high is whatever the HV battery happens to be; the important distinction is that they are kept separate from each other. Yes, a DC:DC converter is used to charge the 12v from HV (previously the job of the alternator), and sometimes the HV can be “bootstrapped” or trickle charged by the 12v (Fords), but both of these tasks are accomplished through induction, so there is no electrical connection (only magnetic).

The systems are kept separate for a critical reason: to keep high voltage under close watch and control. In the car, the 12v system is all around us; we wouldn’t want that with HV. Toyota hybrids constantly check high voltage isolation to confirm integrity of wire insulation, circuit insulation, and battery storage. If there is any HV reference to ground (low voltage), the car can detect it and warn the driver. One short to ground is ok; two shorts is a short of HV through the body (bad).

When the car detects reference between HV and ground it sets trouble code P3009. The Japanese translation is poor; the Mastertech will read “High Voltage Leak Detective”. Again, this is not a fluid leak but continuity between high voltage and low voltage.

Later models will add information subcodes within P3009 to help pinpoint the problem. The gen 2 Prius (and I expect other late models) will not restart (“ready on”) once a high voltage leak is stored.

P3009 is common to gen 1 Prius transmission failures (read more on transmission failures here) when the coils of the electric motor short to the transaxle case or when insulation is otherwise degraded. The short can occur through the transmission fluid too, if it’s old and therefore become conductive, which is why changing the transmission fluid can sometimes help (even though the insulation on the motor windings is definitely deteriorated).

But we at LG are now frequently seeing P3009 on gen 1s due to corrosion internal to the battery. This can be confirmed by clearing trouble codes and then waiting with the key on (ready off) to see if the fault resets. If so, then you know its happening within the battery assembly, since the system main relays (SMRs) are open when the ready light is off.

This is very important because battery corrosion can be cleaned off, even though the dealer will often insist on a whole new battery.

At the bottom of this blog are some close up pics of the corrosion to show how it is reaching the battery cover. The flat side is where the mushroomed deposits have hit the top of the case and are therefore providing continuity.

The prevailing service procedure for checking HV insulation is with a mega-ohmmeter, which applies up to 1000V to the HV line to check for any continuity. But the car does not come equipped with a “megger”, so how does it know when it loses HV insulation? In fact the Battery ECU does provide some reference between low voltage and high voltage to check. I’m not exactly sure how it works (circuitry internal to the ECU), but there is capacitance between HV negative and body ground (hence the need to discharge this capacitance through a multimeter whenever you service the battery). I would just assume it’s a capacitor but the HV reading between negative and ground will change as the car is driven, which tells me it’s not hard wired…

Anyway, I digress. Regardless of the HV reading, the car will have an A/C wave running over this value (see first pic) whenever the key is on (power to the Battery ECU). When there is a short to ground, the ECU’s ability to maintain this wave is reduced (see second pic, smaller wave amplitude). The more direct the short, the more the wave is depressed. I’ve seen direct shorts from plug-in conversions (where secondary HV batteries have had accidental contact to their cases) where the A/C wave was basically gone.

The car checks the performance of this wave, and when it gets too weak, it will set the P3009. If it sets when the car is ready off, we will inspect the battery for corrosion, clean, and reassemble. We can verify the repair with an improved A/C reference wave. The car is fixed, of course, when the P3009 does not return.

Labor to inspect the battery terminals and confirm voltage leak: $240
Labor to clean all terminals and confirm repair: $120

Total: $360

Note this is a lot less money than a new battery, which runs $2300-3000.

One of the few common problems with the Gen 2 Prius (MY 2004-2009) is a leaking output shaft seal from the transaxle, always driver’s side. We’ve seen it on Gen 1 Prius as well, but less frequently. It’s not the end of the world, but there’s no question it should be fixed, since the car seldom leaks otherwise.

When the axle comes out (to access the seal) so too does transmission fluid, so we just include a transmission fluid flush with the service. Since we recommend transmission fluid changes every 30k for all Series/Parallel hybrids (Toyota, Ford, Nissan), we can usually time the seal replacement with a 30k service to stay on track with maintenance intervals.

Prius have two cooling systems: one for the engine and one for the high voltage inverter. They have two separate fill points (see pic: Carolyn’s left hand is pointing to the inverter reservoir, right to the radiator cap).

Technicians failing to fill both systems will cause overheating to whichever system is neglected (illuminating the Master Warning Light (red triangle) and the “check engine” light). I’ve seen this so many times that I’m starting to get angry!!! I mean, if you don’t know (or can’t figure out) that the car has two cooling systems, you have no business working on it!!!!

To be fair, inverter cooling systems are predisposed to another problem (besides unqualified techs) of failing water pumps. Gen 2 inverter water pump issues have been discussed previously: Prius Code P0A93: Inverter Water Pump Failure. But 2001, 2002, and 2003 Prius have the same problem.

At the moment we have three Gen 1 Prius here with inverter cooling issues (with P3130 stored), to which I dedicate this blog.

When Gen 1 Prius inverters overheat, they set a trouble code P3130: Inverter Cooling System malfunction. The next step is to pop the hood and look at the reservoir. Does it have coolant? If not, there is problem #1. Of the three cars here, one was simply left unfilled (system overlooked); the second had the drain plug left loose and consequently lost all its coolant down the road (see pic of dried coolant trail).

If the car has coolant, the next question is whether it’s flowing. Remove the cap on the inverter reservoir (the one ATTACHED to the inverter) and look for turbulence. No turbulence? The car either has air in the system or the pump is stopped.

Find the pump (hint: it’s behind the driver’s headlamp assembly) and put your hand on it. Is it vibrating? Then there’s probably air in the system prohibiting coolant flow. (In this case the pump should also be noisy; you can massage the hoses to work the air out of the system; when it’s quiet and you confirm turbulence in the reservoir, you’re done.) It is possible that the motor is running but the impeller has broken free, in the case that you have vibration but no noise and no turbulence. I have never seen this, but it’s possible. Let common sense guide you.

No vibration? Check the power and ground to the pump, at the connector. I use a noid light; when it illuminates I know the pump is bad; otherwise troubleshoot the circuit.

Of the three cars here, one has a seized pump (it just went bad on its own, which is common); the one with the missing coolant was also disconnected from power (I will have to check it once I fill the system) with the pump actually tucked under the inverter (!) so it appeared to be missing; the third one—with the loose drain plug—has a powered pump that’s now seized from being run without any coolant in the system (which also cools the motor and probably lubricates it too).

To fill and bleed the cooling system LG charges $80 plus tax:

Labor: $60
1 Gallon Super Long Life Coolant: $20

To replace the pump costs $380 plus tax:

Labor: $240
Inverter Water Pump G9020-47022: $140

(Pic of three inverter water pumps today: two for cars and one for inventory)